The child, identified by the initials D.D.B., jumped off the padded side wall of a giant trampoline at Sky High Sports in Bellevue, Wash., and landed in a pit area filled with cushy foam blocks, according to a federal lawsuit.

But instead of a soft landing, D.D.B. "hit his head on an unpadded pole sticking out from the foam pit," the suit seeking money for medical bills and other damages states. Winning the suit may not be easy, however, as Sky High's written waiver may pose too high of a hurdle.

D.B.B.'s suit alleges Sky High was negligent in failing to discover and protect customers from a dangerous condition, namely the unpadded pole.

But Sky High Sports' "Customer Release of Liability and Assumption of Risk" explicitly includes "known and unknown risks" and states, "Flipping and running and bouncing off the walls is dangerous and can cause serious injury and must be done at the participant's own risk.

"Similar risks are also inherent in using the Foam Pit," the waiver continues. If injury occurs, "you or your child may require medical assistance, at your own expense."

Courts have generally upheld such waivers, which are common for inherently dangerous activities (unless that activity takes place on a cruise ship, a federal appeals court recently held). It's not yet clear whether D.B.B.'s guardian signed a waiver, though it's standard practice for the company.

Despite the waiver, Sky High Sports' Bellevue location has been hit with five lawsuits by local personal-injury attorneys in the past six months, Seattle Weekly reports. Sky High's attorney declined to comment about D.B.B.'s trampoline amnesia lawsuit.